We parsed the following live from the Web into this page. Such content is managed by its original site and not cached on Discover Life. Please send feedback and corrections directly to the source. See original regarding copyrights and terms of use.

Alcids (or auks) fill a similar ecological niche in the northern hemisphere as penguins do in the southern hemisphere, except alcids can fly — and can fly long distances. The top photo is of a mixed group of
Rhinoceros Auklets
and
Common Murres
in flight over Monterey Bay in February, some having flown thousands of miles from Alaska to reach that rich pelagic wintering locale.

To quote Nettleship (1996), alcids are "a highly specialized and ecologically diverse group of marine, wing-propelled pursuit-diving birds." Many live at high northern latitudes — like this group of
Atlantic Puffins
and
Razorbills
(left) on Machias Seal Island, Canada — where their fat well-insulated bodies and comical appearances add to the feeling that they recall "northern penguins." Like penguins, though, some species reach tropical latitudes.

In the north Pacific, a diverse set of species pursue krill and bait fish in cold waters throughout the day, coming ashore only during the short breeding season to nest in crevices or offshore islets protected from predators. Some small species only fly to their burrows after dark, so as to avoid predation by gulls. With such a wide variety of species sometimes competing in the same waters, body and bill sizes have distinctly evolved to carve out specialized niches. Two unique Bering Sea alcids are Crested Auklets and the tiny Least Auklets, shown together on St. Lawrence I. (right).

No alcids have a more dramatically modified bill than the three species of puffin. The breeding range of Tufted Puffin is from Alaska to California, with the southernmost permanent colony on the Farallon Islands, 27 mi W of San Francisco. The five species of alcids that nest there have been very well studied over the past few decades (Ainley & Boekelheide 1990), providing much information about, for example, the effects of El Niño on these species. Horned Puffin is more northerly. In an unprecedented invasion, both species were present near-shore on Monterey Bay in spring-summer 2007:
Horned Puffin
(below left) and
Tufted Puffin
(below right).

I live on the shores of Monterey Bay, California, where ten alcid taxa are regular (currently considered 9 species until Xantus's Murrelet
Synthliboramphus h. hypoleucus
and
S. h. scrippsi
are split) , and three more species occur as vagrants. Thus over half of the world's alcids have be recorded here. The local breeder is
Pigeon Guillemot
, which has a black summer plumage (above & right). It nests under the wharves and piers in Monterey harbor and Cannery Row, and can be seen bringing small rockfish to its young (right).

Pigeon Guillemot in Monterey are present from March-October, but nearly the entire population departs during winter. It is believed that these birds migrate north to winter in the Puget Sound vicinity. The very few that remain appear to be in pale first-winter plumage (below left).

Monterey Bay in autumn may host the few subtropical species of alcids.
Craveri's Murrelet
(above right) is a late summer/early fall visitor in warm water years from breeding grounds off Baja California, Mexico. Its identification at sea can be difficult because of "Scripps'" Xantus's Murrelet, but note the black chin on Craveri's. [Its name should be spelled "Craveris' Murrelet" because it was named for two brothers (see Olsen 1996) but checklist committees have, as yet, failed to correct this.]

"
Scripps'" Murrelet
, the northern race of
Xantus's Murrelet
, breeds on the Channel Islands off southern California. Rather little is known of its at-sea biology after the young leave the nesting burrows, but we have found fledglings, still wearing natal down feathers, accompanied by an adult (presumably the father) in mid-summer offshore Monterey (left). Presumably these father-chick 'pairs' have swum that distance, aided by the prevailing currents.

Father-chick 'pairings' are also the norm for Common Murre, which breeds in abundance on the Farallon Islands, and also some offshore rocks along the Big Sur coast. Like most alcids. murres nest in dense colonies. On inaccessible ledges they are so closely packed together that the eggs or chicks are protected entirely by the adults. Many smaller species nest underground in burrows or crevices. Most pairs produce but one young a year.

There were flightless alcids in historic times past, the most recent of which was the Great Auk
Pinguinus impennis
. It occupied boreal latitudes across the north Atlantic, and was easy prey to whalers and eggers. The last pair known were collected for a museum on a small island off Iceland on 2 June 1844.

There is a family book in the uniformly solid Oxford Press series on bird families of the world (Gaston & Jones), but I have not yet seen it. The Atlantic alcidae were thoroughly covered by Nettleship & Birkhead (1985). The account by Nettleship (1996) in the
Handbook of the Birds of the World
series is a very fine introduction.